button7.c

2440 下的5*5按键驱动程序.请参看具体代码内容.

#include <linux/module.h>
#include <linux/init.h>
#include <linux/kernel.h>

#include <linux/sched.h>
#include <linux/timer.h>
#include <linux/interrupt.h>
#include <asm/irq.h>
#include <asm/hardware.h>
#include <asm/uaccess.h>
#include <asm/arch/irqs.h>
#include <asm/io.h>
#include <asm/semaphore.h> 
#include <linux/major.h>
#include <linux/vmalloc.h>
#include <linux/fs.h>

#define key7_MAJOR 138 

#define NOKEY	0
#define KEY7	'7'



static struct semaphore key_sem;
static char key = NOKEY;

devfs_handle_t devfs_key7;


static void  key7_clearirq(void)
{

	SRCPND &= (~0x00000020);  
	INTPND = INTPND;
	EINTPEND &= (~0x00000080); 
}

static void key7_irq_isr(int irq, void *dev_id, struct pt_regs *regs)
{
	key7_clearirq();

	key=KEY7;
	up(&key_sem);
}

static ssize_t key7_read(struct inode *inode, char *buf, unsigned long count)
{
	down_interruptible(&key_sem);
	put_user(key,buf);
	key=NOKEY;
	return 1;
}

int key7_open(struct inode *inode, struct file *file)
{

//	key7_clearirq();
//	enable_irq(IRQ_EINT7);

	
	sema_init(&key_sem,0);
	return 0;
}

void key7_release(struct inode *inode, struct file *filp)
{
//	key7_cleanirq();
//        disable_irq(IRQ_EINT7);

        printk("release ok!\n");
        return;
}


struct file_operations key7_fops = {
	read:key7_read,
	open:key7_open,
	release:key7_release,
};

static int __init key7_init(void)
{
	static int rc;
        unsigned long gpfup;

	set_external_irq(IRQ_EINT7,EXT_FALLING_EDGE, GPIO_PULLUP_DIS);

	
        gpfup = ioremap(0x56000058,8);
        (*(volatile unsigned long *)gpfup) &= 0x7f;  

	disable_irq(IRQ_EINT7);
	enable_irq(IRQ_EINT7);
	


	rc = request_irq(IRQ_EINT7, key7_irq_isr, SA_INTERRUPT, "key7", NULL);
	if (rc) {
		printk("<1>key7irq 1 irq not registered. Error: %d\n", rc);
	}
	
	


        printk("*********key7 init ok!***********\n"); 
      
	/* Register myirq as character device */
        devfs_key7 = devfs_register(NULL,"key7",DEVFS_FL_DEFAULT,key7_MAJOR, 0, S_IFCHR |S_IRUSR |S_IWUSR |S_IRGRP |S_IWGRP,  &key7_fops, NULL);	


/*        if ((rc = register_chrdev(keyirq_MAJOR, "key7", &key7_fops)) < 0) {
		printk("keyirq: can't get major %d\n",keyirq_MAJOR);
		return;
	}	
*/				
	return 0;
}

static void __exit key7_exit(void)
{
        
	disable_irq(IRQ_EINT7);
	

        free_irq(IRQ_EINT7, key7_irq_isr);
       

	devfs_unregister(devfs_key7);

}

module_init(key7_init);
module_exit(key7_exit);

//__initcall(key7_init);